Question

The diagram below shows several of the Moon's positions in its orbit around the Earth. Half of the Moon's surface is lit by sunlight regardless of the Moon's position; however, the amount of lit surface visible from Earth does vary with the Moon's position. Examine the diagram below and answer the question that follows.



Which of the following pictures shows how the Moon appears from Earth when it is at position 1?

Answer 1

I don't see the diagram or the answer choices. Could you upload the picture or tell me where the Sun is in the diagram and where position 1 is around the Earth (e.g. to the right, left, above, below, or at a 45° angle)?

Meanwhile, here's how to decide it yourself:
- The Moon’s illuminated hemisphere always faces the Sun.
- From Earth you see the overlap of the hemisphere facing Earth and the hemisphere facing the Sun.
- If the Moon is between Earth and Sun → new moon (dark from Earth).
- If the Moon is opposite the Sun (on Earth’s far side) → full moon (fully lit).
- If the Moon is 90° east of the Sun (leading Earth in orbit) → first quarter (right half lit as seen from Earth).
- If the Moon is 90° west of the Sun (trailing Earth) → last (third) quarter (left half lit).

Tell me where the Sun and position 1 are in the diagram and I’ll pick the correct pictured phase.